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US 11,381,159 B2Granted
High power density power converter and uninterruptible power supply circuit and methods
AssigneesCornell University, The Regents of the University of Colorado, a body corporate
InventorsKhurram Afridi, Nauman Zaffar, Danish Shahzad
Life of this patent
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Abstract
The present disclosure provides a high-power-density power converter topology with a common neutral between its input and output AC ports while having a single DC bus. The topology may also be embodied as an online uninterruptible power supply (UPS). The presently-disclosed topology enables high power density by utilizing half-bridge switch structures suitable for MHz-frequency operation.
Claims19
A power converter, comprising:
- an AC input having a phase input and a common neutral;
- a DC bus;
- a power factor correction (PFC) rectifier comprising:
- a first half bridge connected from the common neutral to the DC bus, the first half bridge comprising a first switch connected in series with a second switch, the first switch having a closed state and the second switch having an open state when a voltage of the phase input is negative with respect to the common neutral;
- a second half bridge connected from the phase input to the DC bus, the second half bridge comprising a third switch connected in series with a fourth switch, the third switch having a closed state and the fourth switch having an open state when the voltage of the phase input is positive with respect to the common neutral;
- and
- an input inductor having a first end connected between the first switch and the second switch, and a second end connected between the third switch and the fourth switch;
- and
- a controller configured to:
- variably operate the first switch when the voltage of the phase input is positive with respect to the common neutral, and wherein the second switch operates in a complementary manner;
- variably operate the third switch when the voltage of the phase input is negative with respect to the common neutral, and wherein the second switch operates in a complementary manner;
- and
- wherein the operation of the first switch and the third switch is varied to control a current through the input inductor for a unity power factor at the AC input.
10 more elements
A DC-AC power converter, comprising:
- an AC output having a phase output and a common neutral;
- a DC bus;
- an inverter comprising:
- a first inverter half bridge connected from the common neutral to the DC bus, the first inverter half bridge comprising a first inverter switch connected in series with a second inverter switch, the first inverter switch having an open state and the second inverter switch having a closed state when the voltage of the phase output is negative with respect to the common neutral;
- a second inverter half bridge connected from the DC bus to the phase output, the second inverter half bridge comprising a third inverter switch connected in series with an fourth inverter switch, the third inverter switch having an open state and the fourth inverter switch having a closed state when the voltage of the phase output is positive with respect to the common neutral;
- and
- an output inductor having a first end connected between the first inverter switch and the first inverter switch, and a second end connected between the third inverter switch and the fourth inverter switch;
- and
- a controller configured to:
- variably operate the second inverter switch when the voltage of the phase output is positive with respect to the common neutral, and wherein the first inverter switch operates in a complementary manner;
- variably operate the fourth inverter switch when the voltage of the phase output is negative with respect to the common neutral, and wherein the third inverter switch operates in a complementary manner;
- and
- wherein the operation of the second inverter switch and the fourth inverter switch is varied to control a voltage and/or current of the AC output.
10 more elements
A method for DC-AC power conversion, comprising:
- providing a first inverter switch in series with a second inverter switch and connected from a neutral of an AC output to a DC bus;
- switching the first inverter switch and the second inverter switch when a reference voltage and/or current is positive, so as to provide a positive component of an AC voltage and/or current on a phase output of the AC output;
- providing a third inverter switch in series with a fourth inverter switch and connected from the phase output to the DC bus;
- and
- switching the third inverter switch and the fourth inverter switch when the reference voltage and/or current is negative, so as to provide a negative component of the AC voltage and/or current on the phase output.
2 more elements
Dependencies are inferred from the claim text.